Terahertz sensing of sub-nm dielectric film via electron tunnelling

Abstract

Terahertz (THz) sensing of ultrathin layers has been a longstanding challenge due to limitations in conventional detection techniques. In this study, we present a novel approach for sensing sub-1 nm thin dielectric layers based on Fowler-Nordheim (FN) tunneling. Our method exploits the FN tunneling effect at a metal-dielectric interface, enabling sensitive detection of changes in dielectric layer thickness within the THz frequency range. To validate our FN tunneling-based THz sensing technique, we carried out a comprehensive analysis of experimental and simulated data. Our findings demonstrate that this approach exhibits exceptional sensitivity, capable of detecting dielectric layers with thicknesses down to the sub-nanometer scale. Such sensitivity has significant implications for various applications, including nanoscale dielectric characterization, advanced material development, and quality control in microelectronics manufacturing. The FN tunneling-based THz sensing methodology not only overcomes the limitations of traditional detection techniques but also paves the way for novel ultrathin layer sensing capabilities in the rapidly advancing field of terahertz technology. Our study showcases the potential of this groundbreaking technique to revolutionize the THz sensing landscape, offering new opportunities for research and development in various fields.